基于SERS纳米探针的细胞内硝基还原酶检测

Detection of Nitroreductase in Living Cells Based on Surface Enhanced Raman Scattering Nanoprobes

在缺氧的肿瘤细胞内,硝基还原酶(NTR)通常过表达且其含量高低与缺氧程度呈正相关,因此开发高选择性检测NTR的方法对早期肿瘤诊断至关重要.本文通过修饰对硝基苯硫酚(p⁃NTP)到金纳米粒子(Au NPs)表面构建了一种表面增强拉曼散射(SERS)探针.在缺氧条件下,以还原型烟酰胺腺嘌呤二核苷酸(NADH)作为电子供体,NTR可催化还原芳香硝基为芳香胺,导致纳米探针的SERS光谱发生变化,从而实现NTR的高选择性检测,检出限低至18 ng/mL.该探针毒性低、生物兼容性好,可用于缺氧条件下A549细胞内的NTR分析,为肿瘤细胞的缺氧现象评估提供了一种有效的策略.

The expression of nitroreductase(NTR)is closely related to the degree of hypoxic in anoxic tumor cell.Therefore,the development of a highly selective method for the detection of NTR is of great significance for the diagnosis and treatment of cancer.We functionalized p-NTP onto the surface of Au NPs to prepare a highly sensitive SERS probe.Under hypoxic conditions,the reduced nicotinamide adenine dinucleotide(NADH)is used as an electron donor,and NTR can catalyze the reduction of a nitroaromatic compound to an aromatic amine,which results in the SERS spectrum change of the nanoprobe,thus realizing the detection of NTR.The detection limit of the nanoprobe for NTR can reach 18 ng/mL.The probe exhibits low toxicity and good biocompatibility.It can be used for SERS analysis of A549 cells under hypoxia conditions and reveals that the concentration of nitroreductase in tumor cells increases with the increase of hypoxia degree,which pro⁃vides an effective strategy for evaluating hypoxia in tumor cells.